Habitat

Southern ningaui occupy a range of semiarid habitats. They are found in the open heathlands and low mallee scrub of Victoria and South Australia as well as the sandy plains of Western Australia. Southern ningaui are terrestrial. Mallee trunk, shrub roots, leaf litter, woody debris, and bare ground are important habitat components. (Bos and Carthew, 2003; Bos, et al., 2002)

Physical Description

Southern ningaui are small, with a head-body length of 4.6 to 5.7 centimeters and a weight of about 10 to 12 grams. The pelage is uniformly short and light brown. The tail is long, thin and hairless and is roughly the same length as the body. The head is large relative to the body, and has a conical snout with short, thin whiskers. The ears are short and oval. The eyes are round, medium-sized, and black. The manus and pes are small and delicate with thin, long digits. (Bos, et al., 2002; Macdonald, 2006)

Southern ningaui cannot be distinguished from other species in the genus Ningaui by external features alone, making identification difficult in field work. More analytical methods are needed to identify the species. For example, Fisher used allozyme electrophoresis on blood samples to distinguish N. yvonnae from Ningaui ridei in his field study. (Fisher and Dickman, 1993)

Reproduction

The mating system of N. yvonnae appears to be mate defense polygyny, where a male defends an estrous female during her receptive period. Males in captivity are intolerant of one another outside of breeding season. Both sexes produce mate-attracting calls. Males use soft clicks or hisses to attract females and females respond with calls during receptive periods. Males define territories in which they search for mates by marking surfaces, such as bark, with sternal glands. (Jones, et al., 2003; Macdonald, 2006)

Breeding is seasonal, occurring in the spring months. The mating season starts in August and concludes with breeding in October. Females are polyestrous, meaning that they can have several estrous cycles during the breeding season. Polyestrous cycles in N. yvonnae apparently function to replace lost litters, rather than to allow more than one litter per season. Behavioral estrous can last for 1 to 3 days. The maximum length of copulation is 4.5 to 5 hours. Sperm can be stored for 2 to 3 days and sperm competition is unlikely. Females give birth to litters of 5 to 7 young. Southern ningaui reaches sexual maturity between the ages of 6 and 11 months. (Bos and Carthew, 2003; Bos, et al., 2002; Jones, et al., 2003; Krajewski, et al., 2000)

Parental care is performed by the female, who nurtures the young in her pouch. While raising young, females seek protection from predators in shrubs and spiny grasses. These grasses provide the safest environment during the nurturing period when risk of predation is high and females with young in their pouch have more difficulty fleeing rapidly. (Bos and Carthew, 2003)

Lifespan/Longevity

Southern ningaui live for 12 to 14 months in the wild. Lifespan in captivity is not known, since captive animals are usually released shortly after their capture. In the wild most adults die by the fall season beginning in February. At this time, dispersing juveniles comprise about 97% of the population. (Bos, et al., 2002; Ellis, et al., 2008)

Typical lifespanStatus: wild

12 to 14 months

Behavior

Little is known about the behavior of southern ningaui. Only one population of N. yvonnae has been studied in detail. Bos et al. (2002) studied the population of the Middleback Ranges on the Eyre Peninsula in South Australia, located at 137º07’ E and 33º10’S. They are small, fast-running, nocturnal, secretive animals, making it difficult to observe and study in the wild. They are solitary, except during breeding and raising of young. Southern ningaui rest during the day in underground burrows and forage in leaf litter and mallee stem above ground at night. They also forage by “furrowing,” placing the snout in the soil or leaf litter and moving. They occasionally enter spider burrows to eat the inhabitants. Although primarily terrestrial, they have been observed climbing vegetation for brief periods. Southern ningaui move at a slow walk and run from predators with a quadrupedal, bounding gait. They have also been observed licking their fur and using their forepaws to groom. (Bos, et al., 2002; Macdonald, 2006)

Communication and Perception

Communication and perception in small members of the family Dasyuridae, such as N. yvonnae, is poorly understood. Mating vocalizations are the only forms of interspecific communication observed in southern ningaui. (Macdonald, 2006)

Predation

Snakes are the main predators of southern ningaui, particularly those in the family Elapidae. Southern ningaui can escape predation by fleeing along trails, but they prefer to hide, either in burrows or mallee stems. Predator activity, and consequently predator avoidance behavior of N. yvonnae, varies seasonally. The risk of predation is greatest when southern ningaui are found in open habitats such as leaf litter, so they tend to avoid these habitats and seek cover in shrubs and spiny grasses during the warm season, when snake predation is at the greatest risk. Burrows can be used during winter months, when predator risk is lower and keeping warm is a greater priority. (Bos and Carthew, 2003; Bos, et al., 2002)

Ecosystem Roles

Southern ningaui fill a small, terrestrial, insectivore ecological niche in its semiarid habitats. The commensal relationship between N. yvonnae and Triodia species, a genus of hummock-forming grass endemic to Australia, has been well-studied. Triodia provide southern ningaui with both food and protection. The leaves are home to insect prey and provide an ideal foraging habitat. The leaves are pointed and sharp, making it a useful anti-predator defense. Southern ningaui seek habitats with high densities of this grass. There are no reports of Triodia species benefiting from, or being harmed by N. yvonnae. (Bos and Carthew, 2003; Bos, et al., 2002; Ellis, et al., 2008)

Economic Importance for Humans: Positive

Southern ningaui do not have adverse effects on human populations, perhaps due to their small size, remote distribution, and secretive, unobtrusive habits. Bos and Carthew (2003) note that, during their field observations of N. yvonnae, southern ningaui did not seem bothered by the presence of humans and would even forage at the researchers’ feet. (Bos and Carthew, 2003)

Economic Importance for Humans: Negative

There are no known adverse affects of Ningaui yvonnae on humans.

Conservation Status

Southern ningaui are listed as “Least Concern” by the IUCN because of their wide distribution and large populations. Southern ningaui also inhabit some protected areas, including several in western Australia. Currently, there are no major threats to the populations of N. yvonnae, although localized habitat fragmentation is occurring due to mining, sheep grazing, and inappropriate fire regimes. (Ellis, et al., 2008)

Contributors

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.